Improvement in casting belt-pulleys



2 Sheets-Sheet I. A.. L. BRICKNELL.

CASTING BELT PULLEYS. N 183.791. Patented Oct. 31, 1876.

2 Sheets-Sheet 2.

A. L. BRICKNELL.

CASTING BELT PULLEYS.

Patented Oct. 31, 1876.

No.1ea,7e1.

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AUGUSTUS L. BRIGKNELL, OF LONDON, ENGLAND, ASSIGNOB. OF ONE-HALF OF HISRIGHT TO ALEXANDER A. HALL, OF NASHVILLE, TENN.

IMPROVEMENT IN CASTING BELT-PULLEYS.

Specification forming part of Letters Patent No- 183,791, dated October31, 1876; application filed May 4, 1876.

To all whom it may concern:

Be it known that I, AUGUSTUS LEA BRIGK- NELL, a citizen of London,England, at present residing at Nashville, in the county of Davidson andState of Tennessee, have invented certain new and useful Improvements inthe Manufacture of Cast-Metal Belt-Pulleys and I do hereby declare thatthe following specification, taken in connection with the drawingsfurnished and forming a part of the same, is a clear, true, and completedescription of my invention.

My invention has for its object the economical production of cast-metalbelt-pulleys, having belt-faces which are well finished and practicallyconcentric with their axes; and this 1 accomplish without the expensivemachine-work heretofore necessary for producing pulleys having therecited characteristics. It is well known that, owing to the unequalcontraction of the metal, solid cast-iron beltpulleys have belt-faceswhich are irregular in their outline, and not truly concentric to theiraxes, and although such pulleys are sometimes used without theexpenditure of lathework on their faces, their service is far fromsatisfactory, and they are never employed in first-class mills orfactories. It is also well known that solid cast-iron pulleys arefrequently unduly strained, either at the arms or rim, or both, so thatalthough apparently perfect, and of the required strength, they are veryliable to burst or break on receipt of any sudden strain or shock. Toobviate this difficulty large cast-iron pulleys are sometimes cast insegmental sections, subsequently fitted and united, and their facesfinished 0E in a turning engine or lathe.

My invention consists, mainly, in casting the rim of a belt-pulley inone piece, the hub and arms, or their equivalents, in one or morepieces, preferably in one piece, and in uniting the rim thereto whileadjusted and maintained in a position concentric-with the hub.

My invention furtherconsists in casting the rim of a belt pulley in amold having a smooth, well-finished,- permanentface molding-surface anda yielding non-chilling core, whereby a belt face is attained whichrequires no machine-finishing, and the irregular and uneven contractionof the metal is practically' obviated. Belt-pulleys made in accordancewith my invention are readily distinguishable from any others heretoforemade; and my invention further consists in a beltpulley having a solidseparately-cast rim, which is united to the hub and arms by any suitablemeans.

I have demonstrated by practical operations that a pulley constructed inaccordance with my invention is much less expensive than pulleys solidlycast, as heretofore, because the operations of molding and casting aregreatly simplified, and it requires no machinework on its face, eitherfor attaining a desirable belt-surface or for securing concentricity. Mypulleys, too, are stronger than those which are cast solidly, becausethey are never under that strain which is incident to the contraction ofcast metal. It will be obvious, so far as the casting is concerned, thatpulleys cast in segmental sections are more costly than those castsolidly; but if there be more than one arm in any one section, thestrain due to contraction exists to a greater or lesser extent. Thesegmental pulleys also require machine-work on their faces to secureconcentricity, and to afford a proper belt-surface. As compared withthese segmental sectional pulleys, mine are cast at a much less cost,and require, as before stated, no machine-work on their faces.

For permanent-face mold-surfaces I can employ any of the well-knownmatters and compounds-for instance, plaster-of-paris, plumbago, &c. or,as l in practice prefer, a castiron chill may be employed.

To more particularlydescribe myinvention, I will refer to theaccompanying drawings, of which two sheets are furnished.

Figure 1 represents, in perspective, a mold such as I prefer to employfor formingasuitable core. Fig. 2 represents the same in di ametricalvertical section. Fig. 3 represents, ill-sectional view, the sand coreand chills in proper position, and acast pulley-rim remaining in themold. Fig. 4 represents, in perspective, one of my improved pulleys.Figs. 5, 6, 7, and 8 represent different forms of joint between pulleyarms and rim. Fig. 9

represents a pulley having a solid web instead ofarms. Fig. 10represents a hub and its arms. Fig. 11 represents, inperspective, achill bottom side up. Fig. 12 represents, in perspective, a circularbase-plate right side up. Fig. 13 represents, in section, acenteringtable, such as I prefer to employ for adjusting the parts ofwhich my pulleys are composed, and for maintaining them in properposition while being united.

Referring to Figs. 1 and 2, A denotes a baseblock, which constitutes thebottom of my mold. A vertical cylinder, as at a, is mounted centrallythereon, for the purpose of obviating the use of a greater quantity ofsand than is actually requisite for forming a suitable core. Moreover,the core thus formed is better adapted to afford a more uniformresistanee to the contraction of the metal in cooling than would be thecase if no central block were employed. B denotes a sectionalcylindrical shell or core-box, which constitutes the vertical sides ofthe core-mold. Preferably this shell will be made in two pieces, eachbeing semicircular, and of such a height as will render them availablefor casting pulleys with as wide a face as would ever be required onpulleys of a diameter equal that of the mold. The shell B is providedwith apertures b at intervals, for the reception of detachable prints 0.These prints will be of such form and dimensions as may be required ineach case for providing at the inner side of the rim of the pulley apoint of connection with the hub or its arms. For making pulleys withone series of arms, the outside of the shell is provided with anontwardly-projecting flange, as at 0, located midway between top andbottom, and the lower sides of the print-apertures b are in the sameplane with the upper side of the flange 0, so that the prints 0 willhave a good hearing or support thereon. In some instances the prints aremade in one piece, when capable of easy draft, and sometimes in twopieces, in which case they are confined in position by means of across-bar, as at d, and a clamp-screw passing through the flange. Whenthe prints are in two pieces, and set angularly to each other, I providerecesses in the flange and projections on the prints, so that the printsmay be readily and accurately adjusted with relation to each other. Theparts or sections of the shell are united by means of flanged ears andbolts. When the shell is arranged for making pulleys with two series ofarms, it is provided with a flange adjacent in like manner with eachseries of print-apertures b. It is obvious that the depth of the printsmay be varied.

Referring next to Fig. 3, 0 denotes a circular cast-iron base-plate,mounted upon the base-block, and having an interior diameter equal tothe inside diameter of the pulley-rim desired and C denotes a cap-plateof a similar character. 1) denotes a cast-iron chill, preferably cast inone piece, and having its interior surface concaved to a greater orlesser extent, corresponding to the degree of con-' vexity of thebelt-face of the pulley desired, and having a width corresponding withthe width of the face of the pulley-rim to be cast.

Instead of being concaved, the chill-face may be straight, so that forwide straight-faced pulleys two or more chills may be employed, one overthe other.

In Figs. 11 and 12 I show the lower edge of a chill and the uppersurface of the circular base-plate O. The chill is supported by thebase-plate, and to readily adjust and secure them in position relativelyto each other I provide the radial recess d on one, and the radial lugs11 on the other, which, being correspondingly located, operate asdowels, and at the same time admit of the proper unity of the chill andthe plate when they are expanded by heat, as is liable in their use.

With the several parts of the mold thus constructed, I proceed asfollows: The sec tional shell B is placed in proper position, with theprints duly adjusted. The annular space between the central block a andthe shell is then rammed with sand, the detachable prints removedseparately, and the sections of the shell separated and removed, leavingthe cylindrical core as at E, Fig. 3. The circular base-plate O is thenplaced in position, surrounding the core. The inner portion of its uppersurface constitutes a moldsurface for one edge of the pulley-rim. Thechill D is then put upon the base-plate. The space between the innersurface of this chill and the exterior surface of the core E determinesthe thickness of the pulley-rim. The cap-plate O is then placed on topof the chill, which completes the mold, the inner portion of the lowersurface of said cap-plate constituting the moldingsurface of the otheredge of the pulley-rim. With the parts thus adjusted the melted metal ispoured via the gate 0, formed in the inner edge of the cap-plate.

It is in some cases preferable to pour the metal through a vertical ductin the center of the core; thence into the mold by curved or straightlateral ducts to an annular gate recessed into and surrounding the coreat its base, and communicating with the mold by a space equal to abouthalf the thickness of the rim of the pulley desired.

It will be seen that the chill will secure a smooth and proper finish tothe belt-surface of the rim, and that the sand core will permit uniformcontraction, and thereby secure a rim which is practically circular. InFig. 3, at f, I show a support for the circular plate 0, whereby thechill may be set at a proper height with relation to the prints at b.When narrow-faced pulleys are made, the lower series of print-aperturesb in the chill B may sometimes be employed, in which case the plate 0may be placed directly upon the baseblock A. In-general practice,however, the supports f, of various heights, are required for securingaccurate adjustment of the chill.

The hubs of my pulleys may be cast in sand, although I prefer to castthem in vented iron molds, with a view to lessening their cost as far aspossible. However they may be cast, they will be provided with arms,orvin some cases with a web, for connection with the rim.

In Fig. 4 one of my improved pulleys is shown. The rim 9 is separatelycast solidly, on a chill or other permanent mold, as already described,and the hub h separately cast with the requisite number of arms, whichare united to the rimin each instance at 0'.

At Fig. 5, I show a segment of a pulley, illustrating one of the bestconnections known by me for uniting the rim and arms. The prints, beingmade in two parts, as previously referred to, form on the inner side ofthe rim aprojection having a central dovetailed recess, and the adjacentend of the arm is provided with a similar recess. An adjustable handvmold,with or without clay joints, is made to inclose the joint, and themelted iron or other metal is poured therein, which, when cooled,solidly unites the arm and rim. The form of this joint is such, thatthemetal surrounding it has freedom to contract, without in any mannerdisturbing'the relations of the parts; but, on the contrary, saidcontraction is favorable to securing a desirable unity of the parts.

Figs. 6, 7, and 8 represent other forms of joints which may be employedwith good results. Fig. 8 illustrates clearly a wedge interposed betweenthe pulley arm and rim. In some cases a web is desirable between hub andrim instead of arms. Pulleys of this class may readily be made inaccordance with my invention, as it will only involve a shell, B,provided with apertures for prints, which will provide an inward annularprojection from the rim with a serrated edge, and the casting of the hubwith a web having a similar edge, the two parts being united by acast-metal joint, as illustrated in Fig. 9. In some cases pulleys withrims of great width 'require two series of arms. In casting such pulleyssolid- 1y, as heretofore, the unequal contraction of the metal is aserious obstacle to the attainment of good results. It is obvious thatthe arms of the hub must correspond in the positions relatively with theprojections onthe rim with which they are to be united. Should twoseries of projections be cast with the rim they would always be regularand uniform in position with relation to each other; but two series ofarms cast solidly with a hub would seldom be uniform and regularinposition with relation to. each other, owing to their liability to warpand twist'in cooling. In casting a hub with two series of armssolidly ina chill, the metal in that portion of the hub which is between theseries of arms would, in contracting, be fractured, on account of theunyielding character of the chill .and the expansion thereof by heat.Therefore, in making this class of pulleys,I cast a solid rim, as beforedescribed, with the two. series of projections, but cast my hub in twoparts each, with a complete series of arms; or in other words, I casttwo separate hubs each with its arms, as for a pulley with one set ofarms. These two hubs are placed side by side, with their adjacent endsin contact, so that each series of arms will occupy a proper positionwith relation to its proper series of projections on the rim, to whichthey are united, as before described. Inasmuch as the two hub-sectionsare in close contact with each other and are truly reamed, they can bereadily and safely driven to and fro on a shaft longitudinally, andbeing held to the shaft by separate set-screws, they will be unitedtherewith in like manner as if the hub were solid.

For properly adjusting the hubs and rims, I find that it can be quicklyand economically executed by use of a centering-machine, which isillustrated at Fig. 13 in central vertical section.

F denotes a circular table, mounted on a vertical hollow spindle, G, andarranged to rotate thereon. The table is provided with four radialslides, H. which are fitted in radial slots, and are provided with adownwardlyprojecting arm, is, having a tapped hole near its lower end,parallel with its line of motion. The table has also four hangers, as atl, in which are bearings for screws I, which enter the tapped holes inthe arms k of slides H. The inner ends of each screw carries abevelpinion, as at m, which meshes with a large stationary bevel-gear,as at n. It will be seen that if the table F be rotated in onedirection, all the slides will be simultaneously moved outward, and viceversa. At the inner end of each slide H is a longitudinally-slottedadjustable finger, 0, which is secured to the slide by a set-screw, 1),thereby admitting of the nicest adjustment with relation to a centercommon to all of the slides. A mandrel is placed in the hollow spindleG, and a hub placed thereon already properly reamed. A rim is.thenplaced upon the table, which is then rotated, thereby adjusting the rimto a truly concentric position with relation to the hub, and while inthat position the cast-metal joints are formed as near simultaneously aspossible, and the pulley completed.

Instead of having the table movable, it may be stationary, and the geara arranged to rotate on the hollow spindle, so that a crank attached toone of the screws I will, on being rotated, actuate all the screwssimultaneously. While I prefer to use cast metal at the joints betweenrim and the hub or its arms, I am aware that approximately economicalresults may be obtained by uniting the rim with the hub by means ofbolts or rivets, and I do not,

therefore, limit my invention to the use of cast metal at the joints.

- It is to be distinctly understood that my improvements relateexclusively to belt-pulleys, and that my prime object is economy in themanufacture of cast-metal belt pulleys, having, in a practical sense, atruly-concentric rim and a well-finished face.

I am aware that it is not new to make beltpulleys with a wrought-ironrim and cast-metal hub and arm; but such pulleys are devised for specialor extraordinary service, and are con structed, comparatively speaking,regardless of expense.

In connection with the manufacture of wheels for cars and othervehicles, I am well aware that such wheels have been made with aflangedor other rim, cast with its tread on a chill and its rear side on ayielding chilling-core, and that such rims have been united to a hub andarms, or their equivalents, in various ways. It is Well known, however,that the manufacture of car or other similar wheels, considered initself, is an art separate and distinct from that of manufacturingbelt-pulleys. The conditions involved in their manufacture are widelydifferent, although both are produced under the general art of castingmetals. In the car-wheel the heavy rail-flange renders the contractionof the cooling metal comparatively uniform.

A car-wheel constructed with a separate solid flange and separate huband arms, or their equivalents, is more expensive than the solidly-castwheel, and the object of this more costly divisional construction is torender it possible to replace a worn-out rim with a new one withoutdisturbing the hub and axle. The casting of the car-wheel flange-rim onua chill secures a smooth surface; but it has been proven to beadvantageous to turn ofl" the chilled iron to a certain depth, so thatthe originally smooth surface is not available as an item in economy.

With the belt-pulley, a belt-surface which is harder than ordinarycast-iron has no additional value on account of its hardness, thedesired end being a smooth, well-finished surface. The car-wheels haveheavy rail-flanges and treads, involving the use of very considerablebulk of metal, which is heavily distributed throughout the wheel, andtherefore no practical difficulty is experienced in attainingconcentricity of the flange and tread with the axis of the wheel. On theother hand, the rim of a belt-pulley is extremely thin, usually as lightas possible. While the hub and arms necessarily involve the massing ofmore metal than is frequently required for the entire rim. Incidentaland in addition to that prime economy attained by my invention throughlessening the cost of molding and obviating machine-work on thebelt-face, there are other minor points all contributing to the sameend. For instance, I am enabled to use iron of full grade for my rimsand halfgrade iron for my hubs and arms, which in itself is an economicitem of very considerable importance. No

such possibility exists in car-wheels, for none but the highest gradesof iron can be used in their manufacture.

Cast-metal pulleys, as heretofore made with machine-finished faces,must, of necessity, be composed of fine high-grade iron throughout,while, although 1 can use two grades of iron,

as before indicated, a thoroughly serviceable pulley can be made, bymeans of my invention, wholly of low-grade iron, because nomachinefinishing is necessary. It is true that lowgrade iron is not sostrong as the high-grade; but it is to be remembered that in thesolidlycast pulley much strength is requisite for re sistin g the strainincident to contraction,while in my pulley no such strain exists. Now,referring to my mold, it will be obvious that its first cost will beequal to or perhaps greater than the cost of a pattern as usually made,and the flask with which it is used; but it will be seen that the costof a multiplicity of patterns is obviated. An ordinary regularly-gradedlist of pulleys of upward of two hundred in number embraces buttwenty-nine diameters, and therefore twenty-nine core-molds, as employedby me, will be sufficient for producing rims for the entire list, eachcore-mold being suitable for the widest face, and, of course, anynarrower face of the same diameter. So, also, will twenty-nine pairs ofthe circular cap and base plates serve for the entire list and formaking wide straight-faced pulleys, two or more narrow chills may beemployed, one above the other, although, for making convexfaced pulleys,a concaved pulley will be requisite for each diameter and width ofpulley required.

If the hubs and arms be castin a sand mold, the patterns therefor canreadily be made so that additions to hub and arms may be at willprovided, attached or detached, for matching with rims of various widthsof faces.

I am also enabled to cast a hub and arms on a chill, which, while itadds in no manner to their actual value, lessens the cost of casting ascompared with the common methods, and secures a desirable finish. Fromthis comparison of the manufacture of wheels for vehicles with themanufacture of belt-pulleys, it will be seen that my invention is notbased upon previous results in the manufacture of such wheels, for thatwhich rendered those wheels more expensive renders the belt-pulley lessexpensive; also, that the desirable capacities in the carwheel, forinstance, of admitting the replacement of an old flange with anew one,has no value in the belt-pulley; also, although even if a hardenedchilled surface on the car-wheel flange did possess value, which is notthe case, a similar surface on the belt-pulley has no value by reason ofits hardness.

Incidental to my invention, it will be seen that thereby practicallyperfect belt-pulleys may be made with but little outlay for tools, otherthan the molds, which, in cost, will seldom, if ever, exceed cost ofpatterns, as here tofore required in the regular manufacture of pulleysextensively conducted.

For fitting my hubs a reamer is only requisite, and key-slotting, or theset-screw and its threaded seat in the hub,-involves the use of simplemechanisms and the employment of low-priced labor. The centering-machineis readily adapted to pulleys of various diameters. None of theusually-employed face-finishin g tools are requisite, and themanufacture of pulleys is greatly simplified.

Practical operations have demonstrated that pulleys can be made inaccordance with my invention, and in every essential particular fullymeeting the existing requirements of the trade, at a cost of fromtwenty-five to fifty per cent. less than the cost of pulleys of the samesize manufactured by the methods in vogue prior to my invention.

It is to be distinctly understood that I make no claim to the particularconstruction or arrangement of the parts constituting my molds, nor toany particular form of joints between the solid central portion of thepulley and the separately-cast rim, for I am aware that molds somewhatsimilar have been heretofore employed in casting solid belt-pulleys andsectional car-wheels, and that in the manufacture of such car-wheels agreat variety of joints has been proposed at the junction of the rimwith the hub or arms projecting therefrom.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The improvement in the manufacture of cast-metalbelt-pulleys, which consists in casting a solid rim in a mold, having ayielding non-chilling core and a permanent face-surface, substantiallyas described, whereby a well-finished belt-face and a practicallycircular rim are economically attained, as set forth.

2. The improvement in the manufacture of cast-metal belt-pulleys, whichconsists in separately casting the hub and the rim, the former, with itsarms or their equivalents, being cast in any suitable manner, and thelatter cast in a mold having a permanent face-surface and a yieldingnon-chilling core, the two parts being concentrically arranged andunited together at the joints, substantially as described, wherebysmooth-faced and practically concentric pulleys may be economicallyproduced, as set forth.

3. A belt-pulley having a solidly-cast rim and a separately-cast hub,with arms, which are united to the rim, substantially as described.

AUGUSTUS LEA BRIGKNELL.

Witnesses:

WM. 0. W001), PHILIP F. LARNER.

